The major Arab powers once deemed essential to the fight against the Islamic State in Syria and Iraq have largely pulled back from the U.S.-led military campaign, undercutting the Obama administration’s claims about the depth and reach of the coalition it has built with allies in the region.

The Obama administration consistently touts the “65-nation coalition” it has assembled to fight the group also known as ISIS, ISIL and Daesh — but critics say that fewer than a dozen nations today are contributing anything significant to the campaign.

And behind closed doors, administration and military officials admit that air support from such key Arab allies as Jordan, Saudi Arabia, Bahrain and the United Arab Emirates (UAE) — something the White House once touted as an unprecedented and essential part of the coalition — has all but evaporated.

One Pentagon official directly involved in the counter-Islamic State fight told The Washington Times that the Saudis haven’t flown a mission against the group in nearly three months. The official, who spoke on condition of anonymity, said that Bahrain is still involved, but confirmed that Jordan stopped flying sorties against the extremists in August and the UAE hasn’t flown one since March.

A top former Obama administration official who helped build the coalition last year, meanwhile, said that Persian Gulf Arab powers made a strategic gamble months ago to focus their military resources on helping Saudi Arabia wage war against Houthi rebels seen as Iranian proxies in neighboring Yemen — wagering that the U.S. and the European Union would lead the fight against Islamic State.

During the months leading up to last summer’s nuclear deal between Tehran and the West, Yemen had emerged as ground zero for a proxy war pitting Saudi Arabia, the Middle East’s top Sunni Muslim power, and Iran, the region’s largest Shiite power.

The months since have seen waves of Arab air and ground offensives carried out against the Iran-backed Houthi forces in Yemen, with a particularly deadly day occurring in early September, when 45 UAE soldiers and five troops from Bahrain were killed in Yemen.

“They’re eye-deep in Yemen now, and their attention is completely skewed in that direction,” said the former official, requesting anonymity to speak frankly about the situation. “It’s sucked up all the sorties and ground forces that we had wanted to deploy in Iraq and maybe in Syria.”

But the former official said it would be wrong to claim the Saudis and others had completely abandoned the Islamic State effort. “Their calculation was that the Americans would take care of leading the coalition against Daesh while they take care of fighting the Iranians in Yemen,” the former official said.

The catch, according to some longtime Middle East security experts, is that the Obama administration hasn’t done a very good job leading other U.S. allies — in particular Turkey, Germany, Britain, Australia and France — in the counter-Islamic State coalition, while the Arab powers have lost their initial enthusiasm.

“This is a ‘65-country coalition’ of which only about nine are doing something,” said Anthony Cordesman at the Center for Strategic International Studies in Washington, who added that struggling support for the coalition stems in part from the administration’s failure to clearly articulate the goal of its bombing campaign against the extremists in Syria and Iraq.

“I can’t think of a single public document that explained in any coherent way what the strategy is that we have for the air war, or what more needs to be done,” Mr. Cordesman said in an interview. “So I find it difficult to get upset about the lack of allied support, particularly when the Europeans are focused on what’s happening in Europe and the Gulf States are concerned about Yemen.

“There is no sort of automatic tendency of people in the Middle East who have different strategic objectives and goals to follow us, particularly when it isn’t quite clear what our goals are,” he said.

Obama administration officials dismiss such criticisms. One who is directly involved in diplomacy around the counter-Islamic State coalition, and who also spoke on condition of anonymity, told The Times on Tuesday that several Arab powers remain “very much a part of the effort.”

“Even if the airstrikes are not there because of the focus on Yemen, they’re still allowing the use of their bases, and they’re still very much involved with the humanitarian effort and the finance effort.”

The Syrian operations may also get a boost this week as British Prime Minister David Cameron has scheduled a vote in Parliament to expand the U.K.’s more limited bombing mandate to include Islamic State and other jihadis fighting in Syria.

Financial contributions

An internal State Department memo obtained by The Times maintained that the UAE has contributed $1.1 billion in humanitarian aid to Syria and Iraq since 2011, while the Saudis have put forward roughly $36 million, as well as recently donating more than a dozen prefabricated medical camps for Syrian refugees housed in Jordan.

Qatar has also made numerous financial contributions, most recently announcing a pledge of $160 million for an education initiative for Syrian refugees, according to the memo, which also noted that Kuwait has donated at least $800 million.

The Arab powers also continue to provide key intelligence, and the UAE team is co-leading an effort to counter Islamic State propaganda on the Internet.

“They’ve built a center in the Emirates, where our guys are working right there with them to monitor ISIS social media and respond in real time,” said the former top administration official.

But debate over the effectiveness of the U.S.-led coalition against Islamic State has only been heightened during the past month’s wave of international terrorist attacks claimed by Islamic State, which have included the bombing of a Russian passenger jet in Egypt, a double suicide attack in Lebanon and the coordinated Nov. 13 assault on Paris.

While the Paris attacks in particular have spurred European powers to vow deeper support for the coalition, Mr. Cordesman said a coherent strategy for the air campaign is still lacking and “it isn’t quite clear that nations within the region are going to react the same way.”

It’s also worth noting, he said, that “France was already the second-ranking country in terms of the number of sorties it was flying for the coalition before the Paris attacks.”

Others argue that the military action being taken by Washington, the French and even the Russians, who are waging their own air campaign against Islamic State and rebels fighting the Bashar Assad government in Damascus, will ultimately ring hollow without serious buy-in from Sunni Muslim Arab nations — given that Islamic State is a Sunni extremist group.

“The absence of Arab air forces creates a political — not military — void, even though Russia, France and America are fully capable of waging an air war against [Islamic State],” argues Bruce Riedel, a former CIA official who heads The Intelligence Project at the Brookings Institution.

The coalition is missing the “Muslim answer” to Islamic State leader Abu Bakr al-Baghdadi, Mr. Riedel wrote this month in a column for Al-Monitor, a web-based publication focused on the Middle East. “This is a waste of symbolically important resources.”

The Obama administration has tried to encourage the Saudis and other American allies in the Middle East to take a more active and aggressive military role against Islamic State. Defense Secretary Ashton Carter told The Atlantic magazine last month that such nations, including Egypt, would rather build prestigious air forces rather than commit to the dangerous work of countering Islamic State on the ground, as Iran has done.

“If you look at where the Iranians are able to wield influence, they are in the game, on the ground,” Mr. Carter said, citing Tehran-backed military activities in Syria, Iraq, Lebanon and Yemen. “We don’t like it that they’re in the game on the ground, but they are in the game. There is a sense that some of the Gulf States are up there at 30,000 feet.”

But Abdulrahman al-Rashed, a columnist for the London-based Arabic newspaper Asharq Alawsat, countered that several Gulf States are already “in a state of multifront confrontation with Iran as they have been funding the opposition for the last four years in Syria.”

“In Yemen, Saudi Arabia and its Gulf allies are fighting [their] biggest war against followers of Iran, who forcefully seized power and took members of the government hostage,” Mr. al-Rashed wrote in Asharq Alawsat last week. “Iran has always been active in stirring up trouble in the region and has whetted its appetite since the beginning of negotiations on the nuclear deal with the west. It thinks that the west no longer wants to confront it apart from its recent past.”

J. Matthew McInnis, a Mideast-focused fellow with the American Enterprise Institute in Washington, said Mr. Carter has the better case and that “the Saudis in particular need to find other ways to push back against Iran’s activities in the region through more than just purchasing more advanced aircraft and missiles.”

Mr. McInnis said that there is no question the Saudis rank the threat posed by Iran — whether it be in Yemen, Iraq, Syria or elsewhere — above that of Islamic State, which he said is viewed by Riyadh as “a secondary problem.”

“They still recognize ISIS as a problem,” he added. “But since the Iran nuclear deal, they’re really more focused on the Iran threat and, first and foremost for them, that’s in Yemen, where they saw Iran trying to get a foothold.”